A large accounting firm is trying to determine what fee to charge for next year's returns in order to cover potential additional expenses if the client is later subject to an audit. In previous years, the actual mean cost to the firm for attending a client audit session was $650. To determine if this cost has changed, the firm randomly sampled 32 client audit fees and found a mean audit cost of $685 with a standard deviation of $85. Based upon this information, can the accounting firm conclude that the mean audit cost has changed? Use a .05 level of significance for the test.